JPH08257912A - Grinding wheel with conductivity and elasticity, and electrophoretic grinding method therewith - Google Patents

Abstract

PURPOSE: To provide grinding wheel dressing (regenerative) during grinding work by forming an electrophoretic type in-process dressing grinding wheel with conductivity and elasticity out of an abrasive grain and a conductive resin matrix. CONSTITUTION: A grinding wheel 10 used for grinding a prescribed work to be ground by an electrophoretic method has a circular grinding surface at one side, and is formed with a plurality of grinding surfaces apart from each other in the peripheral direction, at prescribed angular intervals from the center of the circle. By mixing a resin matrix abrasive including prescribed abrasive grain with carbon fiber of 5μm or less in diameter, a grinding wheel having conductivity and elasticity is obtained. During grinding work, by making the grinding wheel 10 face a work 30 held in grinding fluid 38 where abrasive grains charged with negative potential are dispersed with the grinding wheel 10 serving as an electrode and positive potential applied, abrasive grains charged with negative potential are attracted to the grinding wheel 10. It is thus possible to dress the grinding surface of the grinding wheel with the abrasive grains in addition to grinding work.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive and elastic whetstone made of a resin (resin) bond abrasive and an electrophoretic polishing method using the whetstone.

[0002]

2. Description of the Related Art Conventionally, a metal-bonded grindstone or wheel in which alumina or diamond abrasive grains are hardened with a metal matrix has been known. Since such a grindstone is hard, it is difficult to bend, and it is necessary to manufacture and use a grindstone having the same curved surface when polishing a curved surface, which complicates the polishing work. Further, when the abrasive grains are worn, the metal matrix rubs against the object to be polished, so that it has a drawback that it meshes with the object to be polished or scratches the polishing surface of the object to be polished.

Regeneration of such a worn metal-bonded grindstone or wheel is carried out by electrolysis to elute the matrix metal on the surface of the grindstone to expose the buried abrasive grains.

On the other hand, a so-called resin-bonded grindstone using a resin (resin) matrix is more flexible than a metal-bonded grindstone and therefore has an advantage that it can be used by bending it into a shape along a required curved surface. Further, there is an advantage that the polishing surface of the object to be polished is not damaged. However, this resin bond grindstone and wheel cannot be regenerated by electrolysis.

Further, carbon fiber is mixed with a resin having elasticity to give conductivity to an electrode, and a voltage is applied to the electrode in a liquid in which charged abrasive grains are dispersed to slide on the surface of the workpiece. It has also been attempted to abrade a work piece with abrasive grains that are moved and electrophoretically attracted to the contact surface of the electrode and the work piece.
Since this method does not use abrasive grains in the electrode, it has the advantage that it does not need to be regenerated and that it is elastically deformed and easily conforms to the curved surface, but the electrode is severely worn and the work piece is removed. Due to the small amount, general practical application is difficult.

[0006]

From this point of view,
Various attempts have been made to impart conductivity to the matrix of resin-bonded grindstones and wheels.

One of them is a method of blending a metal powder such as silver or copper into a matrix. In this case, since water is generally used as the second abrasive grain suspension medium, frictional heat is also generated, the surface of the powder is oxidized, and the conductivity decreases,
There is a drawback that dressing on the polishing surface is insufficient.

Further, a method of blending conductive carbon black into a matrix has been tried, but since the conductivity of such carbon is not so high, it is necessary to increase the amount of carbon added in order to obtain sufficient conductivity. There is. But,
In this case, the matrix strength is lowered, and the strength of the grindstone itself is not sufficient, so that the grindstone is easily broken or the abrasive grains are easily dropped.

Further, when the conductive powder such as the metal powder or carbon black is used, the resin layer enters the contact interface between the powders, and it is difficult for the powders to come into solid contact with each other, so that the electric resistance becomes large. As a result, the powder heats up due to the electric current and expands in volume, causing internal strain in the grindstone and causing embrittlement.

If a small amount of conductive powder is added to such an extent that the strength of the grindstone is not lowered, the electric resistance will be further increased and heat will be generated by the electric current to cause embrittlement of the matrix due to volume expansion. Even if the particle size of carbon black is small, for example, 1 μm or less, such a situation cannot be sufficiently improved.

The use of ordinary carbon fibers is also under consideration. In this case as well, the electric resistivity is lower than that of the powder, but the value is 1 Ωmm or more, which is not low at all, and the same problem as that of carbon black occurs. Further, since the ordinary carbon fiber has a large fiber diameter of 7 to 8 μm, it has a drawback that the second abrasive grains intrude into the portion where the fiber is missing and the regenerating ability is lowered.

Further, the diameter of the ordinary carbon fiber is 7 to 8 μm.
Since the diameter and size of the abrasive grains do not change, it is difficult to uniformly disperse them in all the gaps of the abrasive grains, and there is also a problem that dressing cannot be performed uniformly.

Therefore, a first object of the present invention is to perform dressing (regeneration) of a grindstone during a polishing operation by using a resin matrix having elasticity.

A second object of the present invention is to prevent clogging due to electrophoresis without forming a non-conductive film due to oxidation or the like and without causing heat generation and expansion due to resistance, thereby improving polishing performance. An object of the present invention is to provide a whetstone having conductivity and elasticity capable of maintaining continuity, and an electrophoretic polishing method using the whetstone.

[0015]

In order to achieve the above object, a grindstone having electroconductivity and elasticity according to the present invention, that is, an electrophoretic in-process dressing grindstone, comprises abrasive grains and a conductive resin matrix. Is characterized by.

The electrically conductive and elastic whetstone according to the present invention is characterized by comprising abrasive grains and a resin matrix containing carbon fibers having a diameter of 5 μm or less.

In this case, the carbon fiber contained in the resin matrix may be a graphitized vapor grown carbon fiber.

Further, in the electrophoretic polishing method using a conductive and elastic grindstone according to the present invention, a required voltage is applied to the conductive and elastic grindstone, and the grindstone is charged to a potential opposite to the voltage. The electrophoretic in-process dressing is characterized in that the object to be polished is polished and the grindstone is regenerated at the same time in the liquid in which the second abrasive particles are dispersed.

[0019]

According to the electrically conductive and elastic grindstone of the present invention, the electrically conductive and elastic grindstone is formed by mixing carbon fibers into the resin matrix abrasive containing the required abrasive grains. A positive potential is applied to this as an electrode, and the object to be polished is held in a liquid in which abrasive particles charged to a negative potential are dispersed.
Abrasive particles charged to a negative potential dispersed in the liquid are attracted to the grindstone and are also drawn between the polishing surface of the grindstone and the object to be polished, and these abrasive particles can dress the grinding surface of the grindstone at the same time as the polishing work. it can. As a result, since the polishing surface of the grindstone can always form a new polishing surface, it is not necessary to remove the grindstone for dressing or replace the grindstone when the grinding surface of the grindstone is worn away.

That is, the present invention is characterized in that, as a method of reclaiming a resin bond grindstone or the like, in-process dressing (regeneration) by electrophoretic polishing can be performed during polishing.

As the resin material for forming the resin matrix in the grindstone of the present invention, acrylonitrile / butadiene / styrene resin (ABS resin), nylon, polyethylene, polyester, vinyl ester resin, polyurethane, polycarbonate, polypropylene, polyacetic acid resin Thermoplastic resins such as (PVAC) and butadiene rubber, and thermosetting resins such as epoxy resins and phenol resins can be preferably used.

Here, having elasticity means that it can be deformed by applying a force and can be polished along a curved surface, and it is applicable as long as a normal resin is used for the matrix.

As the abrasive grain material for forming the resin matrix, superabrasive grains such as diamond and cubic boron nitride, alumina (Al ₂ O ₃ ) and SiO 2 are used.
Ordinary abrasive grains such as ₂ and ZrO ₂ can be preferably used. That is, the grindstone here includes a wheel called a so-called super grindstone. On the other hand, as the loose abrasive grains (second abrasive grains on the liquid side), all of the above-mentioned first abrasive grains can be used, but compared with the abrasive grains forming the grindstone (first abrasive grains). Since it does not require so much hardness, it is possible to select an inexpensive one from the economical point of view, and alumina is particularly preferable.

Further, the conductive material has a diameter of 5 μm.
Hereafter, carbon fibers of 3 μm or less are preferable.
As the carbon fiber, a PAN-based carbon fiber or a pitch-based graphite fiber can be appropriately cut and used, but it is preferable that the vapor-grown carbon fiber, especially the graphitized product thereof has a small diameter and high conductivity. .

However, the size of the abrasive grains of the grindstone is determined by the surface roughness of the object to be polished, and the size of the second abrasive grain is larger than that of the grindstone. 1/5
The range of 2 times, more preferably 1/3 to 1.5 times, is preferable from the viewpoint of polishing efficiency, and the case where both are substantially equal (± 30%) is most preferable. In addition, as for the size of the second abrasive grains, the average ratio is 1.
It is preferably 5 times or more.

The content of the abrasive grains in the grindstone is 5
-30% is preferable, and further 9-18% is preferable. On the other hand, as the polishing liquid for dispersing the second abrasive grains, a solution of a polyacrylate salt, a polymethacrylate salt, or a salt of a polymer having a large number of carboxyl groups, such as an aqueous solution, can be used, and a wide range of solutions can be used. Carboxymethyl cellulose (CMC) is preferable because it has a high molecular weight and can be selected. Moreover, this carboxymethyl cellulose is preferable from the viewpoint of efficiently charging the alumina abrasive grains. The concentration of the polymer electrolyte in the polishing liquid also affects the viscosity of the liquid, and since the adsorption performance is different for each combination of the abrasive grains and the polymer electrolyte used, it is determined based on the polishing processability. Is preferred.

Furthermore, in the polishing liquid, use should be made of a polymer having a large number of amino group hydrochlorides that are oppositely charged to the free abrasive grains, and therefore a system in which the voltage of the grindstone and the abrasive grains is reversed from the above. Is also possible. The liquid used as the polishing liquid is generally water, but other polar liquids can be used as long as they can dissociate the polymer and charge the abrasive grains.

[0028]

Embodiments of the electrically conductive and elastic grindstone according to the present invention and an electrophoretic polishing method using the same will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view showing an embodiment of a whetstone having conductivity and elasticity according to the present invention. That is,
In FIG. 1, reference numeral 10 indicates a disc-shaped grindstone. The shape of the grindstone 10 has an annular polishing surface having an outer diameter D _O = 30 mm, an inner diameter D _I = 20 mm, and a thickness t = 5.5 mm on one surface, and a predetermined angle θ from the center O of the circle. =
A plurality (12 in the illustrated example) of polishing surfaces 12 each having a width w = 4 mm and a length l = 5 mm are formed at 30 ° intervals so as to be separated from each other in the circumferential direction. In addition, each polishing surface 12
A groove 14 having a depth h = 1.5 mm is formed in the separated portion.

The grindstone according to the present invention thus constituted was obtained as one having elasticity having an electric resistance of about 10 Ω or less.

Next, a method of performing electrophoretic polishing on a predetermined object to be polished by using the whetstone 10 having the above-mentioned structure and having conductivity and elasticity will be described. Figure 2
Shows a schematic configuration of an apparatus for carrying out the electrophoretic polishing method. That is, in FIG. 2, reference numeral 2
Reference numeral 0 denotes a polishing liquid storage tank. A jig 22 made of a conductive material is formed on a part of the bottom of the polishing liquid storage tank 20, and the bottom surface of the jig 22 is placed on a base 24. It is placed and fixed on the upper portion of the insulating member 26 via the insulator 28. However, the workpiece 30 is placed on the upper surface of the jig 22.

On the other hand, the grindstone 10 having the above-mentioned structure shown in FIG. 1 is supported above the work piece 30 by a support body 32 made of a conductive material, and the support body 32 is made of an insulating material. It is coupled and fixed to a tool mounting spindle 36 of the machine tool via 34.

However, the polishing liquid 38 is stored in the polishing liquid storage tank 20 to a level at which the grindstone 10 is sufficiently immersed in the polishing liquid when polishing the workpiece 30. Further, the support 32 that supports the grindstone 10 and the workpiece 30.
The positive potential terminal 40A and the negative potential terminal 40B derived from the DC power supply 40 are conductively connected to the jig 22 holding.

Using the electrophoretic polishing apparatus having the above structure, the workpiece 30 was polished under the following conditions.

(1) Example Grinding Stone: Alumina having diameters of about 10, 30, and 60 μm was used as abrasive grains, and ABS resin was used as resin. The content of abrasive grains in the grindstone was 12.5 vol%. Then, the set cutting depth t of the grindstone was set in the range of 0 to 10 μm.

Polishing liquid : Carboxymethyl cellulose (CMC) having a molecular weight of about 216,000 is dissolved in distilled water so that the solution viscosity becomes about 30 cP, and the particle size is used as free abrasive grains to be electrophoresed. Is about 10 μm, and the content of the abrasive grains is ρg about 2.
It was added at 5 wt%.

The workpiece: using the wear resistance was preformed working surface about 1MyumRmax, corrosion resistance, aging hardening plastic die steel which has excellent pressure resistance and (AISIP21).

DC power supply : maximum current 5 A, maximum voltage 10
A DC stabilized power supply of 0 V was used, the maximum current was 5 A, and the voltage was applied in the range of 1 to 4 V.

Processing conditions : Spindle speed is 100
The surface was ground at 0 rpm and the electrode feed speed was 2 m / min, and the number of passes of the grindstone with respect to the processed surface was 200.

The results of measuring the removal amount Sr (μm) of the workpiece and the wear amount Sw (μm) of the grindstone at the end of the processing of the workpiece under the above processing conditions are as follows.

1. Removal amount S due to change in carbon fiber diameter Df
Relationship between r and wear amount Sw Vapor grown carbon fiber with diameter Df of 1 μm, PAN of 7 μm
Electrophoretic polishing is performed using a grindstone containing a mixture of carbon-based carbon fibers or 14.5 μm pitch-based graphite fibers cut to about 1 μm and alumina abrasive grains with a particle diameter of 10 μm.
The removal amount Sr of the workpiece and the wear amount Sw of the grindstone were measured.
As a result, as shown in FIG. 3, the removal amount Sr of the workpiece is
It showed a tendency to decrease as the diameter Df was increased. Further, the wear amount Sw of the grindstone showed a tendency to increase as the diameter D was increased. This is because if the diameter Df is increased,
Since the unevenness of the polishing surface of the grindstone became large and the migrated abrasive grains became easy to roll, the abrasion of the grindstone became large, and the second abrasive grain got stuck after the fibers fell out of the grindstone and It is thought that clogging will occur and the amount of workpiece removal will decrease. For comparison, as a result of measurement using only carboxymethylcellulose (CMC) containing no abrasive grains in the polishing liquid, in these cases, the removal amount Sr
It was confirmed that both the wear amount Sw and the wear amount Sw were extremely small.
That is, from these measurement results, the fiber diameter D of the carbon fiber
It can be seen that when f is 5 μm or less, particularly 3 μm or less, the abrasion of the grindstone is small, the amount of the workpiece removed is large, and therefore the processing efficiency is excellent. It is clear that by reducing the fiber diameter Df, the amount of wear of the grindstone with respect to the same amount of workpiece removal is significantly reduced, and the amount of work removal with respect to the same amount of wheel wear is significantly increased.

2. Removal by changing abrasive grain size d
Relationship between the amount Sr and the amount of wear Sw The vapor-grown carbon fiber graphitized product having a diameter of 1 μm and the particle size of 10
Using a grindstone mixed with μm alumina abrasive grains, the particle diameter d of the alumina abrasive grains to be migrated was changed (4 to 20 μm), and the removal amount Sr of the workpiece and the wear amount Sw of the grindstone were measured. As a result, as shown in FIG. 4, the removal amount Sr of the work piece increased in the range of 10 μm or less with the increase of the particle diameter d, and tended to decrease thereafter. Further, the wear amount Sw of the grindstone showed a tendency to decrease as the particle diameter d increased.

This is because the flow resistance r of the migrated abrasive grains is
The following equation (1)

[Equation 1] Where η is the viscosity of the solution, a is the radius of the particle, u is the moving speed of the particle, and the sedimentation speed v of the abrasive grains in the solution is expressed by the following equation (2).

[Equation 2] However, since ρ: particle density ρ 0: solvent density g: gravitational acceleration, when the particle diameter d becomes smaller, the flow resistance r of the migrated abrasive particles becomes smaller and the abrasive surface of the grindstone becomes It's easier to get together. However, it is considered that the removal amount Sr of the workpiece is large and the removal amount Sr of the workpiece is small because the removal amount Sr of the workpiece per unit abrasive grain is small and the abrasive grains are easily rolled.

Further, as the particle size d increases, the removal amount Sr of the workpiece per unit increases, but the flow resistance r of the abrasive particles to be migrated and the sedimentation speed v of the abrasive particles in the solution increase. , It becomes difficult for the abrasive grains to migrate, and the removal amount Sr of the workpiece
It is considered that the abrasion loss Sw of the whetstone and the whetstone decreased.

3. Removal by changing the set cutting depth t of the grindstone
Relationship between the removal amount Sr and the wear amount Sw The amount of removal of the workpiece Sr and the wear amount Sw of the grindstone were measured by changing (0 to 10 μm) the set cutting amount of the grindstone (wear setting dimension of the grindstone) t. As a result, as shown in FIG. 5, when the set cutting depth t of the grindstone is in the range of 1 to 5 μm, the removal amount Sr of the work piece does not change, and tends to increase sharply from around 5 μm. Further, the wear amount Sw of the grindstone showed a tendency to decrease as the set depth of cut t increased.

4. Grinding stone compression load P (N) and compression displacement L
Relation with (μm) With respect to the grindstone used for the measurement based on the change in the set depth of cut t, the compression characteristic regarding the compression displacement L (μm) with respect to the compression load P (N) was measured. As a result, as shown in FIG. 6, the compression load P (N) is the removal amount Sr of the workpiece shown in FIG.
Shows the same change as. From this, it was confirmed that the hardness of the grindstone is related to the removal amount Sr of the workpiece.

(2) Comparative Example Electrode : Eight types of thermoplastic resins (polyethylene-PL, polyurethane-PT,) having different mechanical and physical properties
Nylon 12-NY, Phenolic Resin-PH, Polyester-P
E, ABS resin-A, vinyl ester-VL, epoxy resin
-EP) was mixed with carbon fiber fiber to form an electrode. The blending ratio of carbon fiber to resin is such that the electric resistance is 10Ω or less,
In order to suppress heat generation during processing, it was set to about 50 Vol%.
This electrode was used in place of the grindstone 10 of FIG.

Polishing liquid : Carboxymethyl cellulose (CMC) having a molecular weight of about 216,000 is dissolved in distilled water so that the solution viscosity becomes about 30 cP, and the particle size is used as free abrasive grains to be electrophoresed. Is about 2.3 to 1
Alumina grain of 0 μm was used, and the content rate of the grain was ρ
g was added in the range of about 0.1 to 4 wt%.

The workpiece: Using chromium alloy stainless steel with preformed working surface about 1MyumRmax.

DC power supply : maximum current 5 A, maximum voltage 10
A DC stabilized power supply of 0 V was used, the maximum current was 5 A, and the voltage was applied in the range of 1 to 4 V.

Processing conditions : Spindle speed is 100
The surface grinding method was 0 rpm and the electrode feed rate was 2 m / min.

At the end of processing of the workpiece under the above processing conditions, the processing amount of each workpiece Vr (mm ³ / pas
s) and the amount of electrode wear Vw (mm ³ / pass) were measured and the results are as follows.

1. Processing amount Vr and wear when using each resin
Relationship with the amount Vw When the above eight kinds of thermoplastic resins are used,
The processing amount Vr of the workpiece and the electrode wear amount Vw were measured. As a result, the characteristics shown in FIG. 7 were obtained. In this case, when observing the surface of Nylon 12, fine irregularities in which the carbon fibers had fallen off were confirmed. Therefore, it is considered that, in the case of nylon 12, the highest processing efficiency among the eight types of resin was obtained by holding the migrated abrasive grains on the irregularities, as shown in FIG. 7.

2. Processing amount Vr due to change in applied voltage V
Relationship with wear amount Vw The applied voltage V was changed (0 to 7 V), and the working amount Vr of the workpiece and the electrode wear amount Vw were measured. As a result, FIG.
As shown in, the machining amount V
The increase of r was remarkable. It is considered that this is because the number of abrasive grains that migrated per unit time increased as the voltage increased. Further, the amount of electrode wear Vw showed a tendency to increase in a quadratic curve.

3. Marked as the machining amount Vr due to the change of the abrasive grain size d
Relation with applied voltage V The abrasive grain size d was changed (10 μm, 5 μm, 2.3 μm), and the relation between the processing amount Vr of the workpiece and the applied voltage V was measured. As a result, as shown in FIG. 9, the working amount Vr of the work piece tended to decrease as the abrasive grain size d was decreased. It is considered that this is because the abrasive grains were only buried in the polishing surface of the electrode and were not retained on the polishing surface.

4. Change of abrasive grain content ρg and processing amount Vr
The amount of abrasive grains Vg and the amount of wear Vw of the electrode were measured by changing the content ρg of the abrasive grains (0.1 to 4 wt%). As a result, as shown in FIG. 10, the processed amount Vr of the work piece tended to increase as the content rate ρg of the abrasive grains was increased, and became substantially constant in the vicinity of 2 wt%. It is considered that this is because the carboxymethyl cellulose in the polishing liquid adsorbed to the abrasive grains became insufficient with the increase of the abrasive grain content ρg, and the number of the abrasive grains stably dispersed in the solution decreased. Further, the wear amount Vw of the electrode showed a tendency to increase as the content ratio ρg of the abrasive grains was increased.

[0057]

As is apparent from the above-described embodiments, the conductive and elastic grindstone according to the present invention is constituted by the abrasive grains and the conductive resin matrix, so that the grindstone can be used during the polishing operation. Dressing (playback)
Can be performed easily.

According to the electrically conductive and elastic grindstone of the present invention, the nonconductive film is formed by oxidation or the like by being composed of the abrasive grains and the resin matrix containing the carbon fibers having a diameter of 5 μm or less. It is possible to obtain a grindstone that can prevent clogging due to electrophoresis and maintain continuity of polishing performance without causing heat generation and expansion due to resistance.

Further, in the present invention, a voltage having a required potential is applied to the grindstone, and the grindstone is dispersed in a polishing liquid in which second abrasive grains charged to a potential opposite to the voltage are dispersed.
By carrying out polishing by contacting the object to be polished, the charged abrasive particles dispersed in the liquid are attracted to the grindstone and drawn between the polishing surface of the grindstone and the object to be polished, and these abrasive particles are used for the polishing work. At the same time, the polishing surface of the grindstone can be polished. As a result, since the polishing surface of the grindstone can always form a new polishing surface, when the grinding surface of the grindstone is worn out, the grindstone is removed and regenerated, and the work such as exchanging the grindstone is unnecessary. Excellent advantages are obtained.

Particularly, in the grindstone of the present invention, by changing the particle size of the metal abrasive grains to be electrophoresed or the set cut amount of the grindstone, it is possible to change the regrind (dressing) of the grindstone or the removal amount of the workpiece. I understood. That is,
It is possible to select and set an appropriate one according to the removal amount of the work piece and the reproduction of the grindstone, according to the particle size of the metal abrasive grains to be electrophoresed and the set cutting depth of the grindstone.

In the present invention, the fiber diameter is 7 μm.
The primary stop of operation for cooling or cooling the system, which is necessary in the above, is not necessary for fibers of 5 μm or less.

Further, according to the grindstone of the present invention, by performing the dressing by electrophoresis, it is possible to remarkably improve the polishing performance as compared with the case where the abrasive grains are not migrated, and moreover, it has elasticity. The use thereof can be greatly expanded, and the effect of increasing the productivity of this type of grindstone and increasing the demand level is extremely large.
That is, the grindstone according to the present invention, for example, precision polishing of the mold,
It can be applied for grinding or polishing such as precision lens polishing and silicon wafer polishing. In addition, by dispersing diamond powder mixed in the grindstone into coarse particles down and fine particles up, it is possible to handle from roughing to fine finishing with one grinding wheel, depending on wear. .

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an embodiment of a whetstone having conductivity and elasticity according to the present invention.

FIG. 2 is a schematic cross-sectional configuration diagram of main parts of a polishing apparatus showing an embodiment of an electrophoretic polishing method using a whetstone having conductivity and elasticity according to the present invention.

FIG. 3 is a characteristic diagram showing a relationship between a removal amount of a work piece and a wear amount of a grindstone due to a change in a carbon fiber diameter.

FIG. 4 is a characteristic diagram showing a relationship between a removal amount of a workpiece and a wear amount of a grindstone due to a change in an abrasive grain size to be electrophoresed.

FIG. 5 is a characteristic diagram showing a relationship between a removal amount of a workpiece and a wear amount of a grindstone due to a change in a set cutting depth of the grindstone.

FIG. 6 is a characteristic diagram showing a relationship between a compressive load and a compressive displacement of a grindstone.

FIG. 7 is a characteristic diagram showing the relationship between the processing amount of a workpiece and the amount of electrode wear when using various resins.

FIG. 8 is a characteristic diagram showing a relationship between a machining amount of a workpiece and a wear amount of an electrode due to a change in applied voltage.

FIG. 9 is a characteristic diagram showing a relationship between a machining amount of a workpiece and a wear amount of an electrode due to a change in abrasive grain size.

FIG. 10 is a characteristic diagram showing a relationship between a machining amount of a workpiece and a wear amount of an electrode due to a change in abrasive grain density.

[Explanation of symbols]

 10 Grinding Stone 12 Polishing Surface 14 Groove 20 Polishing Liquid Storage Tank 22 Jig 24 Base 26 Cutting Tool Dynamometer 28 Insulator 30 Workpiece 32 Support 34 Insulator 36 Tool Mounting Spindle 38 Polishing Liquid 40 DC Power Supply 40A Positive Potential Terminal 40B Negative potential terminal

Claims (4)

[Claims] 1. A whetstone for electrophoretic in-process dressing having conductivity and elasticity, which is composed of abrasive grains and a conductive resin matrix. 2. A grindstone having conductivity and elasticity, which is composed of abrasive grains and a resin matrix containing carbon fibers having a diameter of 5 μm or less. 3. The electrically conductive and elastic whetstone according to claim 2, wherein the carbon fiber contained in the resin matrix is composed of graphitized vapor grown carbon fiber. 4. A required voltage is applied to a grindstone having conductivity and elasticity, which is composed of abrasive grains and a conductive resin matrix,
An electrophoretic in-process dressing method characterized in that the grinding stone is regenerated at the same time as polishing the object to be polished in a liquid in which second abrasive grains charged to a potential opposite to the voltage are dispersed in the grinding stone. .